In printing devices and systems, such as in inkjet printing devices and systems, one consideration involves accurate alignment of the printhead assembly nozzles with respect to the X, Y and Z orthogonal reference axes (typically, right-handed) that are defined operatively within the printer (printing device) by the printer""s frame or chassis. Typically, this alignment is one which focuses considerably upon printhead assembly alignment with the scan-axis positioning guide, typically a precision-ground cylindrical rod, often referred to as a carriage rail, along which the support-structure carriage, which carries a printhead assembly, moves back and forth during a printing operation. Such printhead assembly alignment, both translational and rotational, is designed with respect to all three reference axes.
For the purpose of illustration herein, datuming is described in conjunction with a printer""printhead assembly, and the supporting structure provided therefor in the form of a carriage. While another type of direct support structure may specifically be employed, illustration herein with a carriage is intended to represent all other such structures. Because certain details of construction do not form parts of the illustrated embodiments of the present invention, components in the datuming environment of the embodiments of the invention are pictured herein principally in block/schematic forms.
The present invention involves a printing device having a frame which defines therein X, Y, and Z operative, orthogonal axes, plural-site, Z-axis datuming structure operatively interposed a printhead assembly and a carriage supporting that assembly within the device, the Z-axis datuming structure, comprising first and second datuming sites spaced generally in an X-axis direction, and a third datuming site spaced from both the first and second sites in a Y-axis direction, and from at least one of the first and second sites in an X-axis direction.